Finding the Fourth Proportional to 31,075.55, 42,869.57 and 21,007.49

Step by Step Solution

1. Step 1: Write the proportion equation
   31,075.55 : 42,869.57 = 21,007.49 : x
2. Step 2: Convert to fraction form
   31,075.55/42,869.57 = 21,007.49/x
3. Step 3: Cross multiply
   31,075.55x = 42,869.57 × 21,007.49
4. Step 4: Simplify right side
   31,075.55x = 900,581,958.04
5. Step 5: Solve for x
   x = 900,581,958.04/31,075.55
6. Step 6: Final answer
   x = 28,980.40